From 0a326fbc8f72a320051f27328d4d4e7abdfe68d7 Mon Sep 17 00:00:00 2001 From: Rodrigo Siqueira Date: Tue, 5 Nov 2024 08:40:23 -0700 Subject: [PATCH] drm/amd/display: Adjust VSDB parser for replay feature commit 16dd2825c23530f2259fc671960a3a65d2af69bd upstream. At some point, the IEEE ID identification for the replay check in the AMD EDID was added. However, this check causes the following out-of-bounds issues when using KASAN: [ 27.804016] BUG: KASAN: slab-out-of-bounds in amdgpu_dm_update_freesync_caps+0xefa/0x17a0 [amdgpu] [ 27.804788] Read of size 1 at addr ffff8881647fdb00 by task systemd-udevd/383 ... [ 27.821207] Memory state around the buggy address: [ 27.821215] ffff8881647fda00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [ 27.821224] ffff8881647fda80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [ 27.821234] >ffff8881647fdb00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 27.821243] ^ [ 27.821250] ffff8881647fdb80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 27.821259] ffff8881647fdc00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [ 27.821268] ================================================================== This is caused because the ID extraction happens outside of the range of the edid lenght. This commit addresses this issue by considering the amd_vsdb_block size. Cc: ChiaHsuan Chung Reviewed-by: Leo Li Signed-off-by: Rodrigo Siqueira Signed-off-by: Hamza Mahfooz Signed-off-by: Alex Deucher (cherry picked from commit b7e381b1ccd5e778e3d9c44c669ad38439a861d8) Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman --- drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c index a3f17c572bf0..8a152f4974d3 100644 --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c @@ -10725,7 +10725,7 @@ static int parse_amd_vsdb(struct amdgpu_dm_connector *aconnector, break; } - while (j < EDID_LENGTH) { + while (j < EDID_LENGTH - sizeof(struct amd_vsdb_block)) { struct amd_vsdb_block *amd_vsdb = (struct amd_vsdb_block *)&edid_ext[j]; unsigned int ieeeId = (amd_vsdb->ieee_id[2] << 16) | (amd_vsdb->ieee_id[1] << 8) | (amd_vsdb->ieee_id[0]);